256664015 has 8 divisors (see below), whose sum is σ = 321388128. Its totient is φ = 196403680.

The previous prime is 256663991. The next prime is 256664021. The reversal of 256664015 is 510466652.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 256664015 - 2¹⁴ = 256647631 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1115816 + ... + 1116045.

It is an arithmetic number, because the mean of its divisors is an integer number (40173516).

Almost surely, 2^256664015 is an apocalyptic number.

256664015 is a deficient number, since it is larger than the sum of its proper divisors (64724113).

256664015 is a wasteful number, since it uses less digits than its factorization.

256664015 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2231889.

The product of its (nonzero) digits is 43200, while the sum is 35.

The square root of 256664015 is about 16020.7370304865. The cubic root of 256664015 is about 635.5089354117.

The spelling of 256664015 in words is "two hundred fifty-six million, six hundred sixty-four thousand, fifteen".